Structural evolution of oxygen on the surface of TiAlN: Ab initio molecular dynamics simulations

Fangyu Guo, Jianchuan Wang, Yong Du, David Holec, Pengfei Ou, Hao Zhou, Li Chen, Yi Kong

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7 Citations (Scopus)

Abstract

We have employed ab initio molecular dynamics simulations to study the oxidation behavior of TiAlN hard coatings as a function of Al content and temperature. Results show that for TiAlN with a low Al content (Ti 0.75 Al 0.25 N), Ti atoms can always bond with O atoms, while Al atoms bond with O only at a higher temperature. For Ti 0.5 Al 0.5 N, both Al and Ti can bond with O atoms, irrespective of temperature. Through analyzing the displacement height of O-bonded metal atoms, we suggest that titanium oxide nucleates at the outermost layer of Ti 0.75 Al 0.25 N while the outermost layer after Ti 0.5 Al 0.5 N is exposed to oxygen is aluminum oxide. Our simulation results predict, in agreement with experiment, that Ti 0.5 Al 0.5 N has superior oxidation resistance in comparison with Ti 0.75 Al 0.25 N. This study provides an atomistic insight to the initial stage of the oxidation process, which is else difficult to observe experimentally.

Original languageEnglish
Pages (from-to)520-525
Number of pages6
JournalApplied surface science
Volume470.2019
Issue numberMarch
DOIs
Publication statusPublished - 22 Nov 2018

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